Research, theory and clinical observations point to attentional percursers as responsible for learning failures in the retarded. Even the severely retarded can be taught discriminations errorlessly, however, providing evidence that appropriate attention is present throughout acquisition. Errorless learning paradigms do improve learning capacity in this population. They have failed to achieve widespread use because of their complexity and cost. Touchette (1971) demonstrated the feasibility of a simpler approach. Discriminative stimuli are presented, followed after a brief delay be a prompt which guarantees an appropriate response. The method has shown promise as a therapeutic technique. It has not been researched to determine optimal parameters, breadth of application or diagnostic implications. We propose a series of studies which focus on anticipatory behavior in the severely retarded, and the transfer of attention which can occur when a salient stimulus is paired which a neutral stimulus. We will measure anticipatory behavior in order to quantify the probability of attention shift associated with diagnostic categories, procedural parameters and stimulus characteristics. If particular interest is the modifiability of impulsive or inertial response tendencies, and the likelihood of cumulative effects which result from repeated exposures to errorless discrimination training. The proposed technique offers the possibility that "learning sets" and abstract concepts could be taught without errors to this population with severe attentional disorders.